Railway signaling



NOV. 2, 1937. PFLASTERER 2,097,822

RAILWAY S IGNALING Filed July 18, 1936 3 Sheets-Sheet 1 Fig. 1A.

INVENTOR George 13. flasieren HIS ATTORNEY Nov. 2, 1937. G. R. PFLASTERER 2,097,822

RAILWAY SIGNALING Filed July 18, 1936 3 Sheets-Sheet 2 INVENTOR George 12. lastere BY Z HAS ATTORNEY Nov. 2, 1937. G. R. PFLASTERER 2,097,822

' RAILWAY SIGNALING Filed July 18, 1956 3 Sheets-Sheet 3 INVENTOR George 2.

HIS ATTORNEY Patented Nov. 2, 1937 PATENT OFF-ice RAILWAY SIGNALING George R. Pflasterer, Swissvale, Pa., assignor to The .Union Switch & Signal Company, Swissyale, Ta a corporation ,ofPennsylvania illpplication July 18, 1936, Serial No. 191,418

.13 Claims.

Myinvention relates to railway Signaling, and particularly to railway signaling involving wayside signals for governing the passage of trains along a stretch of track. Specifically, my invention relates to new and novel means for supplying a current of distinctive character'to the rails of each of three sections in the rear of an occupied section'whereby there is produced a threeblock, four-indication, system of signaling. My invention is, in part, an improvement upon that disclosed and claimed in an application for United States Letters Patent, Serial No. 26,784, filed June 15, 1935, by James 'J. Vanhorn, for Railway signaling.

I will describe two forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

Figs. 1A and 1B of the accompanying drawings are diagrammatic views, which when placed end to end in the order named, illustrate one form of apparatus embodying my invention. Fig. 2 is a diagrammatic view illustrating a modification of a portion of the apparatus shownin Figs. 1A and 1B, and also embodying my invention.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1A and 1B, the reference characters I and 2 designate the rails of a stretch of track over which traffic normally moves in the direction indicated by the arrows. The stretch is divided by insulated joints 3 into track sections WX, XY, and Y-Z. Located at the entrance to each track section is a signal designated by a suitable distinguishing reference character. Each signal includes an upper indication unit U and a lower indication unit L. As here shown, each upper indication unit U is a semaphore arm capable of assuming a horizontal or stop position, and a-45" or caution position, and a vertical or proceed position. Each lower unit U is a semaphore arm capableo'f assuming a horizontal or stop position and a vertical or proceed position.

For controlling the signals, each section is provided with a polarized direct current track relay and with a neutral direct current track relay designated by the reference characters ATR and BTR, respectively, each with a prefix the same as the reference character of the associated signal. Each direct current track relay ATR is connected directly across the rails of the associated track section and each neutral track relay BTR is connected across the rails of thea'ssociated section by an asymmetric unit, a transformer, and a condenser designated by the reference characters'Q, P, and J, respectively, each with a prefix the same as the reference character of the associated signal. As will be explained more in detail hereinafter, the rails of each section are at times supplied with direct current only and at other times supplied with alternating current-simultaneously with direct current. The impedance of the polarized track relays A'IR isof-such value that the flow of alternating current in these relays will be substantially prevented. The transformers P will prevent the flow of direct current from the rails into the neutral track relays BTR and the condensers J will pre- -vent' the flow of direct current from the rails into the primary windings of the transformers P.

Each sec'tion'is provided with a source of direct current here shown as a batteryanddesignated by the reference character 'TB with a prefix the same as the reference character of the associated signal. v

For controlling "the polarity of the direct current supplied to the track circuit in the rear, each section is provided with a pole changing relay designated by the reference character PC with a prefix the same as the associated signal. As will .be explained'more in detail hereinafter, each 'PC relay isenergized when the associated track relay "BTR. 'is energized or when the associated track relay ATR is energized in the normal direction provided the associated track relay BTR is then deenergized.

"For supplying alternatingcurrent to the rails of the section next in rear, each section is provided "with a transformer having a secondary winding Ill and a primary winding l I. Each secondary winding I is connected'between the associated battery TB and the rails of the section next-in rear.

:Eor supplying alternating current to the primary winding "H of the transformers N, each "section is provided with a device designated by the reference character A with a prefix the same as the associated signal.

Ashere shown, each device A is an alternator of 'the vibrating reed type. Referring to alternator 'Z A, for example, an elastic member i2 is caused :Ito vibratebetween terminals l3 and M by a controlwinding l5. In-the deenergized condition of alternator A, member I? does not connect with either terminal 13 or T4 but does connect with a terminal I6. When-energy is supplied to the al- -ternator, winding l 5 will attract member l 2 causing it to connect with terminal Hi and to move away from terminal 16, causing winding l5 to "becomedeenergi-zed. 'Upon the deenergization of winding l 5, the resilience of member l6 will cause it to move away from terminal M and to connect with terminal 53 as well as with terminal IS. The circuit for winding i 5 being then again completed through terminal l6, winding IE will again attract member !2 causing the cycle of operation just described to be repeated. Winding l5, therefore, will be repeatedly energized anddeenergized as long as energy is supplied to its control circuit. When member IE is in engagement'with contact E3, the left-hand portion of primary winding 5 i of transformer 1N will be energized in one direction, whereas when member I 6 is in engagement with contact l4, the'right-hand portion of primary winding M will be energized in the reversed direction. Alternating current, therefore, will be induced in secondary winding H) of transformer TN as long. as alternator 7A is operating.

The track relays ATR and BTR control the signals in the following manner; When relay ATR is deenergized (see signal 3) ,both semaphore arms U and L of signal 8 will be caused to assume the horizontal position to indicate stop. When relay ATR is energized in'the reverse direction (see signal 1), a caution circuit for the upper semaphore arm U of that signal is closed so that that signal is displaying its upper semaphore arm in the caution position and its lower semaphore arm L in'the stop position to indicate approach next signalprepared to stop. This caution circuit may be traced from terminal B of any suitable source of energy through front'contact of relay "iATR and semaphore arm U to terminal C of the same source of energy When the relay ATR is energized in the reverse direction and the relay BTR, is also energized, the caution circuit for the upper semaphore arm U remains closed and a proceed circuit for the lower semaphore arm L is closed so that signal 6 displays its upper semaphore arm U in the caution position and its lower semaphore arm L in the proceed position to indicate approach next signal at medium speed. The proceed circuit for the lower semaphore arm L may be traced from terminal B over front contact 24 of relay EATR, reverse polar contact 2223 of relay eATR, fronttcontact- 2 4 of relay SBTR, and lower semaphore arm L to terminal C. When relay ATR is energized in the normal direction (see signal 5), the caution circuit for the upper semaphore arm U remains closed and a proceed circuit for the upper semaphore arm is closed so that signal 5 is caused to display its upper semaphore Uv in the proceed position and a lower semaphore arm L in the stop position to indicate proceed at normal speed. The proceed circuit may be traced from terminal B over front contact 25 of relay 5ATR, normal polar contact 2226 of relay 5ATR,-and upper semaphore arm U to terminal C.

As here shown, a train K is indicated diagrammatically in thesection immediately to the right of location Z so that both relays BATR and 8BTR are deenergized. Under this condition, the rails of section Y-Z are supplied with direct current of reverse polarity so that relay 'EATR is energized in the reverse direction. The circuit for relay 'IA'I'R may be traced from one terminal of track battery 8TB through resistor 21, backpoint of contact 28 of relay 8P0, secondary winding ID of transformer 8N, rail l, relay 'lATR, rail 2, and back point of contact 29 of relay 8P0 to the other terminal of track battery 8TB.

Since relay 'lATR, is energized in the, reverse direction and relay lBTR is deenergized a circuit is closed to cause the operation of alternator 1A. This circuit may be traced from terminal B over back point of contact 30 of relay TBTR, front contact 3! of relay 'IATR, reverse polar contact 3233 of relay TATE, and alternator A to terminal C.

Since relay lPC is deenergized and secondary winding H); of transformer IN is energized by alternating-current, the rails of section XY are supplied with direct current in the reverse direction and with alternating current so that relay BATR is energized in the reverse direction and relay SBTR also is energized. The circuit for relay B ATR may be traced from one terminal of track battery 7TB through resistor 21, back point of contact 3 of relay 'lPC, secondary winding IU of transformer EN, rail I, relay BATR, rail 2, and back point of contact 35 of relay lPC to the other terminal of track battery 1TB. The circuit for the energization of relay EBTR may be traced over the same'path as'just described for relay EATR except including condenser fiJ, transformer SP, and asymmetric unit 6Q in place of relay BATH. 7

Since relay EBTR is energized, relay BPC also is energized over the front point of contact 36 of relay SBTR so that direct current is supplied in the normal direction to the rails of section WX to cause relay EATR to be energized in the normal direction. The circuit for relay 5ATR may be traced from one terminal of track battery 6TB through resistor 21, front point of contact 31 of relay BPC, rail 2, relay EATR, rail secondary winding H3 of transformer 6N, and front point of contact 38 of relay GPC to the other terminal of track battery 5TB. Since relay 5ATR is energized in the normal direction and relay SBTR is deenergized, the relay 5PC will be energized to supply the rails of the section immediately in the rear of location W with direct current in the normal direction so that the signal (not shown) for such rear section will be displaying the normal proceed indication.- The circuit for relay 5P0 may be traced from terminal B over the back point of contact 39 of relay BBTR, front point of contact 40 of relay EATR, normal polar contact 32'4l of relay 5ATR, and relay EPC to terminal C.

The relays PC are provided with a slow-releasing characteristic in order that these relays will not release during the period when they are being transferred from control by the front point of the associated relay BTR to control by the back point of such relay B'I'R and the associated relay ATR. For example, when the train K vacates the section immediately to the right of location Z so that relay SBTR becomes deenergized and relay SATR. becomes energized in the normal direction to cause signal 6 to display the normal proceed indication, the relay. GPC, even though momentarily deenergized, will not become released during this period to disturb the energization of the rails for the section W-'X.

Referring now to Fig. 2, I have shown herein one signal and associated apparatus which, when connected in a system, will provide three-block, four-indication, signaling similar to that described for the apparatus shown in Figs. 1A

and 1B. V

The reference character CTR designates an alternating current polarized track relay connected by a condenser J to the rails of the section associated with the signal and the reference character DTR designates a neutral direct current relay also connected to the rails of such associated section. Associated with the relay CTR FIG aoa'neaa is a winding '42 which is permanently connected to :any convenient source of alternating :current, the terminals of which are designated by the reference charactersTBX and CX. The impedance of the relay DTR will ibe of .such value as to prevent the flow of alternating current in this relay and the condenser J will prevent the flow of direct current in the relay CTR.

For supplying direct current to the rails of the :rear section, the usual track battery TB .isprovided, and for supplying alternating current to the railsof the rear section, a transformer M is provided having a primary winding 43 and a secondary winding M. The ,primary winding 43 is connected to the terminals BX and CK of the source of alternating current and the secondary.

winding 44 is connected across the rails in one direction or the other in accordance with the condition of an alternating current pole changing relay designated by the reference character PCX.

The relays CTR. and DTR control the semaphore arms U and L in a manner identical to that described for the relays ATR and BTR shown in Figs. lAand 1B. Since the signal control circuits may be very readily traced, it is not considered necessary to give a detailed description of these circuits.

When the relays CTR and DTR are both deenergized the relay PCX will also be deenergized to supply alternating current in the reverse direction to the rails of the rear section over the back points of contacts 45 and 46 of relay PCX and ,back point of contact 41 of relay CTR.

When relay CTR is energized in the reverse direction and relay DTR is deenergized, direct current will be supplied to the rails of the rear section simultaneously with alternating current in the reverse direction over back points of contacts 45 and 46 of relay PCX and front point of contact 41 of relay CTR.

When either relay DTR, is-energized, or relay CTR is energized in the normal direction and relay DTR is deenergized, relay PCX will be energized to supply alternating current in the normal direction to the rails of the rear section over front points of contacts 45 and 46 of relay PCX. One circuit for relay PCX may be traced from terminal BX over front point of contact is of relay DTR and the other circuit may be traced from terminal BX over the back point of contact 48 of relay DTR, front contact ,49 of relay CTR, and normal polar contact 5ll-5l of relay CTR.

The relay PCX is provided with a slow releasing characteristic so that its front points will not become open to disturb the energization of the rails of the rear section during the time this relay is being transferred from control by the front point of contact 48 of relay DTR to control by the back point of contact 48 and relay CTR.

Although I have herein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A railway signal system comprising a plurality of sections of railway track, means effective when one section is occupied to supply the rails of the section next in rear of such occupied section with only direct current of one polarity, means then effective to supply the "rails of the section second in rear of such occupied section with :alternating current simultaneously with direct current of said 'one :polarity'provided the section next .in rear of such :occupie'd .section is unocrcupied, :means then e'ifectiverto vsupply the rails i of the section :third linrear of such occupied sec- :Ttion with only direct current of the other polarcity provided the .second section in rear of such occupied section l'ls also unoccupied, andtrafiic governing means for each section selectively responsive itoathe :character and number of currents supplied to the of the associated sec- .tion.

.2. In combination, "a forward section-and a rear :section of :ra'i'lwayitrack, .a polarized track relay and :a neutral itrack :relay for the forward section, means effective when'the forward section is unoccupied to energize only the polarized relay .Jin :the :reverse direction or to energize the neutral relay simultaneously "with the energization of the polarized relay'in thereverse direction or to energizeronly the polarized .relayvin the normal direction according to traffic conditions in advance of the forward section, means effective when both thepolarized and neutral relays are deenergized to supply the rails of the .zrear section with current of one character, means effective when the polarized relay is energized :in the reverse direction and the neutral relay is deenergized to supply the rails of the rear section with current of a different character.simultaneously with current of said one character, and means effective when the neutral relay energized or when the polarized relay is energized in the normal direction provided the neutral relay is deenergized to supply the rails'of the'rear section with current of still a different character.

B. In combinatioma forward section and a rear section of railway track, a'polarized track relay and a neutral track'relay for the forward section, means effective when the forward section is unoccupied to energize only the polarized .relay in the reverse direction or to energize the neutral relay simultaneously'with'the energization of the polarized relay in the reversedirection or to energize only the polarized relay in the normal direction accordingto trafiic conditions in advance of the forward section, a pole changing relay which is energized when the neutral relay is energized or when the associated polarized relay is energized in the normal direction provided the neutral relay is then deenergizedmeans for supplying the rails of the rear section with current of one character or of another character according'assaid pole changing relay isienergized or deenergized, respectively, and means for supplying the rails of the rear section with current of .a different character simultaneously with current of said, other character effective when said polarized relay is energized in the reverse direction provided said neutral relaylis then deenergized.

4. In combination, a forward section and a rear section of railwaytra'ck, a polarized track relay and aneutral trac'k'relay forthe forward section, means effective when the forward section is unoccupied to energize only the polarized relay in the reverse directionlor to energize the neutral relay simultaneously with the energization of the polarized relay in the reverse direction or to energize only the polarized relay in the normal direction according to traffic conditions in advance of the forward section, a pole changing relay which is energized'whenxthe neutral relay is energized or when the associated polarized relay ais' energized .in the normal direction provided "the neutral relay is then deenergized, means for supplying the rails of the rear section with current of one character-or another character according as said pole changing relay is energized or deenergized respectively, and means for supplying the rails of the rear section withycurrent of a different character simultaneously with current of said other character effective when said pole changing relay 'is deenergized provided said polarized relay is then energized.

5. In combination, a forward section and a rear section of railway track, a polarized track relay and a neutral track relay for the forward section, means effective when the forward section is unoccupied to energize only the polarized relay in the reverse direction or to energize the neutral relay simultaneously with the energization of the polarized relay in the reverse direction or to energize only the polarized relay in the normal direction according toztrafflc conditions in advance of the forward section, a pole changing relay, a circuit for saidpole changing relay including a front contact of the neutral relay, another circuit for said pole changing relay including a back contact of the neutral relay as well as a front neutral contact and a normal polar contact both of the polarized relay, and means including said pole changing relay for governing the current supplied to the rails of said rear section.

6. In combination, a forward section and a rear section of railway track, a polarized track relay and a neutral track relay for the forward section, means effective when the forward section is unoccupied to energize only the polarized relay in the reverse direction or to energize the neutral relay simultaneously with the energization of the polarized relay in the reverse direction or to energize only the polarized relay in the normal direction according to traffic conditions in advance of the forward section, a pole changing relay which is energized when the neutral relay is energized or when the associated polarized relay is energized in the normal direction provided the neutral relay is then deenergized, means for supplying the rails of the rear section with direct current of one polarity or of the other polarity according as said pole changing relay is energized or deenergized respectively, and meansincluding an alternator for supplying the rails of the rear section with alternating current simultaneously with direct current of said other polarity effective when the neutral relay is deenergized provided the polarized relay is then energized in the reverse direction.

7. In combination, a forward section and a rear section of railway track, a polarized track relay and a neutral track relay for the forward section, means effective when the forward section is unoccupied to energize only the polarized relay in the reverse direction or to energize the neutral relay simultaneously with the energization of the polarized relay in the reverse direction or to energize only the polarized relay in the normal direction according to traific conditions in advance of the forward section, a pole changing relay which is energized when the neutral relay is energized or when the associated polarized relay is energized in the normal direction provided the neutral relay is then deenergized, means for supplying the rails of the rear section with direct current of one polarity or the other polarity according as said pole changing relay is energized or deenergized respectively, a transformer having a primary winding and a secondary winding, said secondary Winding being connected inseries with the rails of the section next in rear, and means for supplying said primary winding with alternating current when said polarized relay is energized in the reverse direction provided said neutral relay is then deenergized.

8. In combination, a forwardsection and a rear section of railway track, a polarized track relay and a neutral track relay for the forward section, means effective when the forward sec tion is unoccupied to energize only the polarized relay in the reverse direction or to energize the neutral relay simultaneously with the energization of the polarized relay in the reverse direction or to energize only the polarized relay in the normal direction according to traiiic conditions in advance of the forward section, a pole changing relay which is energized when the new tral relay is energized or when the associated polarized relay is energized in the normal direction provided the neutral relay is then deenergized, means for supplying the rails of the rear section with direct current of one polarity or the other polarity according as said pole changing relay is energized or deenergized respectively, a transformer having a primary winding and a secondary winding, said secondary winding being connected in series with the rails of the section next in rear, an alternator for each section having its output terminals connected to said primary winding, and a circuit for said alternator including a back contact of the associated neutral relay as well as a front neutral contact and a reverse polar contact both of said polarized relay.

9. In combination, a forward and a rear section of railway track, a polarized track relay and a neutral track relay for the forward section, means effective when the forward section is unoccupied to energize only the polarized relay in the reverse direction or to energize the neutral relay simultaneously with the energization of the polarized relay in the reverse direction or to energize only the polarized relay in the normal direction according to trafiic conditions in ad vance of the forward section, a pole changing relay for the forward section which is energized when the neutral relay is energized or when the polarized relay is energized in the normal direction provided the neutral relay is then deenergized, means effective to supply the rails of the rear section with only alternating current of reverse polarity when the pole changing relay is deenergized provided the polarized relay also is deenergized, means effective to supply the rails of the rear section with direct current simultaneously with alternating current of reverse polarity when the pole changing relay is deenergized provided the polarized relay is energized, and means effective to supply the rails of the rear section with only alternating current of normal polarity when the pole changing relay is energized.

10. In combination, a forward and a rear section of railway track, a polarized track relay and a neutral track relay for the forward section, means eifective when the forward section is unoccupied to energize only the polarized relay in the reverse direction or to energize the neutral are relay simultaneously with the energization of the when the neutral relay is energized or when the polarized relay is energized in the normal direction provided the neutral relay is then deenergized, a source of direct current, a transformer provided with a primary winding and a secondary winding, said primary winding being connected to a source of alternating current, means including a back contact of said pole changing relay and a back contact of said polarized relay for connecting said secondary winding across the rails of the rear section in one direction, means including a back contact of said pole changing relay and a front contact of said polarized relay for connecting said source of direct current across the rails of the rear section in series with said secondary winding in said one direction, and means including a front contact of said pole changing relay for connecting said secondary winding across the rails in the other direction.

11. In combination, a forward and a rear section of railway track, a polarized track relay and a neutral track relay for the forward section, means effective when the forward section is unoccupied to energize only the polarized relay in the reverse direction or to energize the neutral relay simultaneously with the energization of the polarized relay in the reverse direction or to energize only the polarized relay in the normal direction according to trafiic conditions in advance of the forward section, a pole changing relay for the forward section which is energized when the neutral relay is energized or when the polarized relay is energized in the normal direction provided the neutral relay is then deenergized, a source of direct current, a source of alternating current, means effective to connect said source of alternating current across the rails in one direction or the other according as said pole changing relay is energized or deenergized respectively, and means effective to connect said source of direct current in series with said alternating current when said pole changing relay is deenergized provided said polarized relay is then energized.

12. A railway signal system comprising a plurality of sections of railway track, means effective when only one section is occupied to supply the rails of the section next in rear of such occupied section with only alternating current of one polarity, means then effective to supply the rails of the section second in rear of such occupied section with direct current simultaneously with alternating current of said one polarity provided the section next in rear of such occupied section is unoccupied, means then effective to supply the rails of the section third in rear of such occupied section with only alternating current of the other polarity provided the second section in rear of such occupied section is also unoccupied, and traffic governing means for each section selectively responsive to the character and number of currents supplied to the rails of the associated section.

13. In combination, a forward and a rear section of railway track, a polarized track relay and a neutral track relay for the forward section, means effective when the forward section is unoccupied to energize only the polarized relay in the reverse direction or to energize the neutral relay simultaneously with the energization of the polarized relay in the reverse direction or to energize only the polarized relay in the normal direction according to trafiic conditions in advance of the forward section, a pole changing relay for the forward section which is energized when the neutral relay is energized or-when the polarized relay energized in the normal direction provided the neutral relay is then deenergized, a source of direct current, means effective to connect said source of direct current across the rails of the rear section in the normal direction or the reverse direction according as said pole changing relay is energized or deenergized respectively, and means for also supplying alternating current to the rails of the rear section effective when said polarized relay is energized in the reverse direction provided said neutral relay is then deenergized.

GEORGE R. PFLASTERER. 

